package string;

import javax.swing.*;

/**
 *  StringBuilder的演示
 */
public class StringBuilderDemo {
    public static void main(String[] args) {
        String str = "好好学习Java";
        //复制str的内容到builder中----好好学习Java
        StringBuilder builder = new StringBuilder(str);

        //append():追加内容----在末尾追加
        builder.append(",为了找个好工作");
        System.out.println(builder);//好好学习Java,为了找个好工作

        //replace():替换部分内容(含头不含尾)
        builder.replace(9,16,"就是为了改变世界");
        System.out.println(builder);//好好学习Java,就是为了改变世界

        //delete():删除部分内容(含头不含尾)
        builder.delete(0,8);//删除下标为0-7的字符
        System.out.println(builder);//,就是为了改变世界

        //insert():插入内容(从下标开始插入)
        builder.insert(0,"活着");
        System.out.println(builder);//活着,就是为了改变世界



        /*
        //StringBuilder的创建方式:
        StringBuilder builder1 = new StringBuilder();//空字符串
        StringBuilder builder2 = new StringBuilder("abc");//abc串

        //String与StringBuilder互转:
        String str = "abc";
        //将字符串str转换为StringBuilder类型,并赋值给builder3
        StringBuilder builder3 = new StringBuilder(str);//abc串
        //将StringBuilder类型转换为String类型,并赋值给str2
        String str2 = builder3.toString();

         */





























    }
}
